Improvement in step-ladders



W4. L. PTTEH'.J

- Step-Ladder. y 10,161,059 l PPPPPP ed, MMMMM 23,1375.

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UNITED STATES WILSON L. POTTER, OF HARTFORD, CONNECTICUT.

IMPROVEMENT IN STEP-LADDERS.

Specification forming part of Letters Patent No. 161,059, dated March 23, 1875 application :filed January 25, 1875.

To all whom it may concern:

Beit known that I, WILsoN L. POTTER, of Hartford, in the county of Hartford and State of Connecticut, have invented an Improved Combined Step-Ladder and Shelf, of which the following is a specification, reference being had to the accompanying drawing, where- Figure l is a perspective view of a step-ladder and shelf combined embodying my said improvements. Fig. 2 is a View of the same, folded up, in longitudinal section, the plane of the section being one side or off the center. The shelf is not folded down.

The device is a folding step-ladder, with a `folding shelf attached thereto, making use of adaptations of the principle of the toggle or knee joint for the adjustment of the ladder and of `the shelf for use.

I denote the Whole of the ladder proper by the letter a, to which ladderis hinged the supporting-frame b. When the ladder is adjusted for use the frame b is swung out, as shown in Fig. l; when folded up, the ladder and the frame lie together, as shown in Fig. 2. The free ends of the ladder and frame are connected by the two pieces c c, hinged, respectively, to the ladder and frame, and also hinged together, thus constituting a knee or toggle joint, and it is set centrally of the ladder and frame, so as to dispense with the necessity for more than one of these joints. The shelf d is hinged to the frame b, and is connected to one of the cross-bars of this frame by toggle-joint parts e c, hinged at the ends and hinged together.

The use of these togglejoints for these purposes has peculiar practical advantages: When the apparatus is folded up there are no loose or dangling ends or pieces to be knocked or broken oi; the apparatus folds up in the most compact possible manner 5 the ends of the joints being connected permanently to other parts, an uninstructed user has no difculty in adjusting the device for use or in folding it up-he can make no mistake; the adjustments are accomplished by a single movement; the construction is a strong and sure one; and withal it is cheap.

I claim as my invention- The combination of the ladder a, the hinged frame b, the centrally-set toggle-joint c, the hinged shelf d, and the toggle-joint c, all substantially as and for the purpose set forth.

l WILSON L. POTTER.

Witnesses: v

WM. E. SIMoNDs, JAs. S. BAIsDEN.

PATENT QEFIG. 

